We studied the vegetation degradation and its correlation with rainfall interception and soil in rocky desertification area of northern Guangdong with methods of site investigation, station-oriented observation and simulated test. The results showed that: In accordance to the light, middle, severe and extremely severe rocky desertificaiton, the plant community succession was from Herb+liana+shrub+Arbor to herb to bryophyta, the community's layer was from 4 layers to 4 layers to 2 layers to 1 layer; the average height was from 87.06 cm to 63.32 cm to 42.13 cm to 6.21 cm; proportion of species reduction was from 0% to14% to 46% to 86%; the dominant species of plants were from Pistacia chinensis+Boehmeria nivea+Vitex negundo+Pueraria phaseoloides to Pistacia chinensis+Artemisia apiacea+Chrysanthemum indicum to Miscanthus floridulu+Arundinella anomala+Eleusine indica to bryophyta; the Margalef index was from 2.33 to 2 to 1.25 to 0.33; the Shannon-Wiener index was from 2.96 to 2.31 to 1.94 to 0.42. There is a significant correlation both between vegetation degradation and rainfall and between vegetation degradation and soil.